* Re: pktgen and spin_lock_bh in xmit path
From: Eric Dumazet @ 2009-10-21 5:14 UTC (permalink / raw)
To: Ben Greear; +Cc: NetDev, robert, David S. Miller
In-Reply-To: <4ADE9560.5050500@candelatech.com>
Ben Greear a écrit :
> Eric Dumazet wrote:
>> pktgen should not use "clone XXX" pkts if macvlan is used (or any
>> other driver
>> that ultimatly calls dev_queue_xmit() and queue packet), since skb
>> queue anchor
>> is shared and would be overwritten.
>> After some thoughts, I believe user is in error :)
> I tried to explain in my original post: The problem arises when
> when the hard-start-xmit fails with NETDEV_TX_BUSY. Part of the
> hard-start-xmit logic for virtual devices can call dev_queue_xmit, which
> can ultimately
> change the queue mapping and yet may still return NETDEV_TX_BUSY.
>
> pktgen would try to resend this skb next loop, and this is where it would
> blow up.
>
> I have a patched macvlan logic and a patched dev queue xmit logic that
> allows
> me to return NETDEV_TX_BUSY when underlying device fails to transmit.
>
> It may be that my hacked macvlan is the only virtual device that could ever
> return NETDEV_TX_BUSY, and if that is the case, I don't think the bug
> could ever be hit in official kernel code. My opinion is that the
> current pktgen code makes
> too many assumptions, so unless there is a performance penalty, I still
> think it should be cleaned up. But, I may be too paranoid.
If a virtual device changes skb->queue_map, it must consume skb,
or it breaks caller.
Alternative would be to restore queue_map to its initial value in
your hacked macvlan when it wants to return NETDEV_TX_BUSY status.
We could add a WARN_ON(skb_get_queue_mapping(pkt_dev->skb) != queue_map);
in pktgen, to catch driver errors but pktgen assumption is right IMHO
@@ -3466,6 +3471,7 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev)
/* fallthru */
case NETDEV_TX_LOCKED:
case NETDEV_TX_BUSY:
+ WARN_ON(skb_get_queue_mapping(pkt_dev->skb) != queue_map);
/* Retry it next time */
atomic_dec(&(pkt_dev->skb->users));
pkt_dev->last_ok = 0;
^ permalink raw reply
* Re: pktgen and spin_lock_bh in xmit path
From: Krishna Kumar2 @ 2009-10-21 5:12 UTC (permalink / raw)
To: Ben Greear; +Cc: David S. Miller, Eric Dumazet, NetDev, netdev-owner, robert
In-Reply-To: <4ADE2735.9000807@candelatech.com>
Ben Greear <greearb@candelatech.com> wrote on 10/21/2009 02:40:13 AM:
Coming back a bit to this post:
> > - queue_map = skb_get_queue_mapping(pkt_dev->skb);
> > + queue_map = pkt_dev->cur_queue_map;
> > + /*
> > + * tells skb_tx_hash() to use this tx queue.
> > + * We should reset skb->mapping before each xmit() because
> > + * xmit() might change it.
> > + */
> > + skb_record_rx_queue(pkt_dev->skb, queue_map);
> > txq = netdev_get_tx_queue(odev, queue_map);
>
> I think that must be wrong. The record_rx_queue sets it to queue_map +
1,
> but the hard-start-xmit method (in ixgbe/ixgbe_main.c, at least), takes
the
> skb->queue_map and uses it as an index with no subtraction.
But that should work fine. record_rx_q sets queue_mapping to +1,
but skb_tx_hash calls skb_get_rx_queue, which does a -1 on this
value, and updates that value into queue_mapping. Hence it will
not cross the txq boundary. Drivers can use the queue_map value
directly without requiring to subtract.
Thanks,
- KK
>
> This causes watchdog timeouts because we are calling txq_trans_update in
pktgen on
> queue 0, for instance, but sending pkts on queue 1. If queue 1 is ever
> busy when the WD fires, link is reset.
^ permalink raw reply
* Re: pktgen and spin_lock_bh in xmit path
From: Ben Greear @ 2009-10-21 5:32 UTC (permalink / raw)
To: Krishna Kumar2
Cc: David S. Miller, Eric Dumazet, NetDev, netdev-owner, robert
In-Reply-To: <OFE19FAAE4.E89690B3-ON65257656.001B6B90-65257656.001CA0C0@in.ibm.com>
Krishna Kumar2 wrote:
> Ben Greear <greearb@candelatech.com> wrote on 10/21/2009 02:40:13 AM:
>
> Coming back a bit to this post:
>
>
>>> - queue_map = skb_get_queue_mapping(pkt_dev->skb);
>>> + queue_map = pkt_dev->cur_queue_map;
>>> + /*
>>> + * tells skb_tx_hash() to use this tx queue.
>>> + * We should reset skb->mapping before each xmit() because
>>> + * xmit() might change it.
>>> + */
>>> + skb_record_rx_queue(pkt_dev->skb, queue_map);
>>> txq = netdev_get_tx_queue(odev, queue_map);
>>>
>> I think that must be wrong. The record_rx_queue sets it to queue_map + 1,
>>
>> but the hard-start-xmit method (in ixgbe/ixgbe_main.c, at least), takes the
>> skb->queue_map and uses it as an index with no subtraction.
>>
>
> But that should work fine. record_rx_q sets queue_mapping to +1,
> but skb_tx_hash calls skb_get_rx_queue, which does a -1 on this
> value, and updates that value into queue_mapping. Hence it will
> not cross the txq boundary. Drivers can use the queue_map value
> directly without requiring to subtract.
>
When using pktgen on real physical hardware, there is none of the
skb_tx_hash or dev_queue_xmit
logic called, just the hard-start-xmit. That is why it fails to update
the proper queue with
his first patch.
On virtual devices like mac-vlans, the logic probably worked ok since it
goes
through dev_queue_xmit.
Thanks,
Ben
--
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc http://www.candelatech.com
^ permalink raw reply
* Re: pktgen and spin_lock_bh in xmit path
From: Ben Greear @ 2009-10-21 5:40 UTC (permalink / raw)
To: Eric Dumazet; +Cc: NetDev, robert, David S. Miller
In-Reply-To: <4ADE989A.90209@gmail.com>
Eric Dumazet wrote:
> Ben Greear a écrit :
>
>> Eric Dumazet wrote:
>>
>>> pktgen should not use "clone XXX" pkts if macvlan is used (or any
>>> other driver
>>> that ultimatly calls dev_queue_xmit() and queue packet), since skb
>>> queue anchor
>>> is shared and would be overwritten.
>>> After some thoughts, I believe user is in error :)
>>>
>> I tried to explain in my original post: The problem arises when
>> when the hard-start-xmit fails with NETDEV_TX_BUSY. Part of the
>> hard-start-xmit logic for virtual devices can call dev_queue_xmit, which
>> can ultimately
>> change the queue mapping and yet may still return NETDEV_TX_BUSY.
>>
>> pktgen would try to resend this skb next loop, and this is where it would
>> blow up.
>>
>> I have a patched macvlan logic and a patched dev queue xmit logic that
>> allows
>> me to return NETDEV_TX_BUSY when underlying device fails to transmit.
>>
>> It may be that my hacked macvlan is the only virtual device that could ever
>> return NETDEV_TX_BUSY, and if that is the case, I don't think the bug
>> could ever be hit in official kernel code. My opinion is that the
>> current pktgen code makes
>> too many assumptions, so unless there is a performance penalty, I still
>> think it should be cleaned up. But, I may be too paranoid.
>>
>
> If a virtual device changes skb->queue_map, it must consume skb,
> or it breaks caller.
>
> Alternative would be to restore queue_map to its initial value in
> your hacked macvlan when it wants to return NETDEV_TX_BUSY status.
>
Yeah, that sounds fine to me, should be easy and cheap.
> We could add a WARN_ON(skb_get_queue_mapping(pkt_dev->skb) != queue_map);
> in pktgen, to catch driver errors but pktgen assumption is right IMHO
>
> @@ -3466,6 +3471,7 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev)
> /* fallthru */
> case NETDEV_TX_LOCKED:
> case NETDEV_TX_BUSY:
> + WARN_ON(skb_get_queue_mapping(pkt_dev->skb) != queue_map);
> /* Retry it next time */
> atomic_dec(&(pkt_dev->skb->users));
> pkt_dev->last_ok = 0;
>
That looks good too.
Thanks,
Ben
--
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc http://www.candelatech.com
^ permalink raw reply
* Re: [PATCH] Allow renaming of network interfaces that are up.
From: Nix @ 2009-10-21 6:50 UTC (permalink / raw)
To: Stephen Hemminger; +Cc: Matt Mackall, linux-kernel, netdev
In-Reply-To: <20091021103846.2f985ea1@s6510>
[Cc:s adjusted, thanks davem]
On 21 Oct 2009, Stephen Hemminger said:
> On Tue, 20 Oct 2009 19:54:02 +0100
> Nix <nix@esperi.org.uk> wrote:
[...]
>> This makes it much easier to use things like netconsole which bring up a
>> network interface before userspace has started: presently these will cause
>> interface renamings to fail, breaking any userspace that relies on renaming
>> devices to avoid reliance on the potentially-unstable kernel-assigned name.
[...]
> This breaks quagga and other applications that track renames.
So it's only userspace that's the problem? We have a choice of breaking
apps that assume that only downed interfaces can be renamed, and thus
breaking routing while the system is running, or breaking userspaces
that assume that they can rename interfaces, and thus breaking routing
at bootup when netconsole is on? Great :/
(How many systems run things that track renames? Is this, ew, a reason
to make this constraint configurable, maybe even at runtime, so you
could start with interfaces renameable and then lock them down once
static route assignment is up, just before you fire up quagga?)
^ permalink raw reply
* Re: Enable syn cookies by default
From: Olaf van der Spek @ 2009-10-21 7:17 UTC (permalink / raw)
To: netdev
In-Reply-To: <b2cc26e40910150159q68ce555fs4b1683969d939d25@mail.gmail.com>
On Thu, Oct 15, 2009 at 10:59 AM, Olaf van der Spek
<olafvdspek@gmail.com> wrote:
> On Sat, Oct 10, 2009 at 3:01 PM, Olaf van der Spek <olafvdspek@gmail.com> wrote:
>> Hi,
>>
>> I'm forwarding Debian feature request #520668.
>>
>> Could syn cookies be enabled by default?
>>
>> AFAIK syn cookies only get send when the half-open TCP connection
>> queue is full. So stuff like window scaling should work fine in normal
>> situations.
>>
>> Speaking of which:
>> When the half-open TCP connection queue is full and syn cookies are
>> enabled, you get a message like "kernel: possible SYN flooding on port
>> 2710. Sending cookies."
>> However when syn cookies are disabled, you don't get any message (in
>> kern.log), although connections to your server are timing out.
>> Could such a message be added?
>> Maybe with a suggestion to increase the size of that queue or to
>> enable syn cookies.
>>
>> Greetings,
>>
>> Olaf
>>
>> http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=520668
>> http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=520667
>> https://bugs.launchpad.net/ubuntu/+bug/57091
>>
>
> Somebody?
Anybody?
^ permalink raw reply
* Re: Enable syn cookies by default
From: Eric Dumazet @ 2009-10-21 7:25 UTC (permalink / raw)
To: Olaf van der Spek; +Cc: netdev
In-Reply-To: <b2cc26e40910210017v3885b18dre5021c8a920f30d7@mail.gmail.com>
Olaf van der Spek a écrit :
> On Thu, Oct 15, 2009 at 10:59 AM, Olaf van der Spek
> <olafvdspek@gmail.com> wrote:
>> On Sat, Oct 10, 2009 at 3:01 PM, Olaf van der Spek <olafvdspek@gmail.com> wrote:
>>> Hi,
>>>
>>> I'm forwarding Debian feature request #520668.
>>>
>>> Could syn cookies be enabled by default?
>>>
>>> AFAIK syn cookies only get send when the half-open TCP connection
>>> queue is full. So stuff like window scaling should work fine in normal
>>> situations.
>>>
>>> Speaking of which:
>>> When the half-open TCP connection queue is full and syn cookies are
>>> enabled, you get a message like "kernel: possible SYN flooding on port
>>> 2710. Sending cookies."
>>> However when syn cookies are disabled, you don't get any message (in
>>> kern.log), although connections to your server are timing out.
>>> Could such a message be added?
>>> Maybe with a suggestion to increase the size of that queue or to
>>> enable syn cookies.
>>>
>>> Greetings,
>>>
>>> Olaf
>>>
>>> http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=520668
>>> http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=520667
>>> https://bugs.launchpad.net/ubuntu/+bug/57091
>>>
>> Somebody?
>
> Anybody?
This is a user selectable setting. What's wrong with /etc/sysctl.conf ?
^ permalink raw reply
* Re: Enable syn cookies by default
From: Olaf van der Spek @ 2009-10-21 7:48 UTC (permalink / raw)
To: Eric Dumazet; +Cc: netdev
In-Reply-To: <4ADEB752.50103@gmail.com>
On Wed, Oct 21, 2009 at 9:25 AM, Eric Dumazet <eric.dumazet@gmail.com> wrote:
> Olaf van der Spek a écrit :
>> On Thu, Oct 15, 2009 at 10:59 AM, Olaf van der Spek
>> <olafvdspek@gmail.com> wrote:
>>> On Sat, Oct 10, 2009 at 3:01 PM, Olaf van der Spek <olafvdspek@gmail.com> wrote:
>>>> Hi,
>>>>
>>>> I'm forwarding Debian feature request #520668.
>>>>
>>>> Could syn cookies be enabled by default?
>>>>
>>>> AFAIK syn cookies only get send when the half-open TCP connection
>>>> queue is full. So stuff like window scaling should work fine in normal
>>>> situations.
>>>>
>>>> Speaking of which:
>>>> When the half-open TCP connection queue is full and syn cookies are
>>>> enabled, you get a message like "kernel: possible SYN flooding on port
>>>> 2710. Sending cookies."
>>>> However when syn cookies are disabled, you don't get any message (in
>>>> kern.log), although connections to your server are timing out.
>>>> Could such a message be added?
>>>> Maybe with a suggestion to increase the size of that queue or to
>>>> enable syn cookies.
>>>>
>>>> Greetings,
>>>>
>>>> Olaf
>>>>
>>>> http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=520668
>>>> http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=520667
>>>> https://bugs.launchpad.net/ubuntu/+bug/57091
>>>>
>>> Somebody?
>>
>> Anybody?
>
> This is a user selectable setting. What's wrong with /etc/sysctl.conf ?
It requires user action...
Often you notice cookies are disabled only after a service becomes unreachable.
What's wrong with improving defaults?
Don't forget the missing log entries.
Olaf
^ permalink raw reply
* Re: [PATCH RFC] Per route TCP options
From: Gilad Ben-Yossef @ 2009-10-21 8:04 UTC (permalink / raw)
To: Rick Jones; +Cc: netdev, ori
In-Reply-To: <4ADDE4C4.5080501@hp.com>
Rick Jones wrote:
> Gilad Ben-Yossef wrote:
>> Turn the global sysctls allowing disabling of TCP SACK, DSCAK,
>> time stamp and window scale into per route entry feature options,
>> laying the ground to future removal of the relevant global sysctls.
>>
>> You really only want to disable SACK, DSACK, time stamp or window
>> scale if you've got a piece of broken networking equipment somewhere
>> as a stop gap until you can bring a big enough hammer to deal with
>> the broken network equipment. It doesn't make sense to "punish" the
>> entire connections going through the machine to destinations not
>> related to the broken equipment.
>
> Is it really only the case that those options get disabled for broken
> networking equipment? Does this presage making all TCP options
> per-route only?
Well, I assume it might be the case that there are situations where you
are trying to communicate over some exotic link where the networking
equipment is not broken as such, but the unusual properties of the link
makes one of the features not desirable. I can't think of such a
situation right now off the top of my head, but maybe they exist.
The point is that even then you are more then likely to wish to turn off
these options to specific destination and routes (that go over said
exotic link) and keep using them over others - e.g. timestamp OK for
local LAN, but for default route that goes over exotic TCP/IP over
carrier penguins turn it off.
To sum it up, I think making these options per route is a win no matter
the situation. The question I am less certain about if it is also
desirable to have a global kill switch in addition to the per route
options. My gut feeling is that this is not needed once you have a per
route option.
Cheers,
Gilad
--
Gilad Ben-Yossef
Chief Coffee Drinker & CTO
Codefidence Ltd.
Web: http://codefidence.com
Cell: +972-52-8260388
Skype: gilad_codefidence
Tel: +972-8-9316883 ext. 201
Fax: +972-8-9316884
Email: gilad@codefidence.com
Check out our Open Source technology and training blog - http://tuxology.net
"Sorry cannot parse this, its too long to be true :)"
-- Eric Dumazet on netdev mailing list
^ permalink raw reply
* Re: [PATCH RFC] Per route TCP options
From: Gilad Ben-Yossef @ 2009-10-21 8:10 UTC (permalink / raw)
To: David Miller; +Cc: netdev, ori
In-Reply-To: <20091020.173653.193717720.davem@davemloft.net>
David Miller wrote:
> When sending more than one patch in a patch set, you must
> number your patches so that people know in what order your
> pathes should be applied.
>
> Mailing lists and other entities reorder list postings
> quite severely, so it's not "obvious" what order your
> postings matter just based upon arrival order.
>
>
Yes, of course. How silly of me not to notice. My apologies.
git and I are currently have a bit of love hate thing going on...
I will re-send the patch set in a more favorable form.
Thanks,
Gilad
--
Gilad Ben-Yossef
Chief Coffee Drinker & CTO
Codefidence Ltd.
Web: http://codefidence.com
Cell: +972-52-8260388
Skype: gilad_codefidence
Tel: +972-8-9316883 ext. 201
Fax: +972-8-9316884
Email: gilad@codefidence.com
Check out our Open Source technology and training blog - http://tuxology.net
"Sorry cannot parse this, its too long to be true :)"
-- Eric Dumazet on netdev mailing list
^ permalink raw reply
* Re: [PATCH RFC] Per route TCP options
From: Gilad Ben-Yossef @ 2009-10-21 8:15 UTC (permalink / raw)
To: Ilpo Järvinen; +Cc: Eric Dumazet, Netdev, ori
In-Reply-To: <Pine.LNX.4.64.0910202151160.22058@melkinkari.cs.Helsinki.FI>
Hi Ilpo,
Ilpo Järvinen wrote:
>
>> Specifically, I couldn't understand why sysctl_tcp_ecn is documented to be a
>> boolean value, but is initialized to 2 and queried with if (sysctl_tcp_ecn ==
>> 1) so I decided to let it be until I figure it out... ;-)
>>
>
> Ah, I didn't notice that "- BOOLEAN" there so I modified only the
> description (some blindness to caps perhaps :-)), did you perhaps read
> it fully?
>
>
Yes, I did finally. What threw me off was that that
TCP_ECN_create_request() were the value if checked as a boolean was
inlined in the include file. I've missed that. Thanks for the tip.
At any rate, it means that "noecn" is not a good route option feature,
since it is not boolean. I plan to handle those in the next patch set,
if the current one is accepted.
Thanks,
Gilad
--
Gilad Ben-Yossef
Chief Coffee Drinker & CTO
Codefidence Ltd.
Web: http://codefidence.com
Cell: +972-52-8260388
Skype: gilad_codefidence
Tel: +972-8-9316883 ext. 201
Fax: +972-8-9316884
Email: gilad@codefidence.com
Check out our Open Source technology and training blog - http://tuxology.net
"Sorry cannot parse this, its too long to be true :)"
-- Eric Dumazet on netdev mailing list
^ permalink raw reply
* Re: [PATCH RFC] Allow to turn off TCP window scale opt per route
From: Gilad Ben-Yossef @ 2009-10-21 8:18 UTC (permalink / raw)
To: Stephen Hemminger; +Cc: netdev, ori
In-Reply-To: <20091021104024.32adab23@s6510>
Stephen Hemminger wrote:
> On Tue, 20 Oct 2009 17:22:39 +0200
> Gilad Ben-Yossef <gilad@codefidence.com> wrote:
>
>
>> Add and use no window scale bit in the features field.
>>
>> Signed-off-by: Gilad Ben-Yossef <gilad@codefidence.com>
>> Sigend-off-by: Ori Finkelman <ori@comsleep.com>
>> Sigend-off-by: Yony Amit <yony@comsleep.com>
>>
>
> The same effect can by just using window limit on route
>
Actually, not exactly. There is a subtle but important difference
between "I support window scaling, but choose a scale of 0", which is
what your suggestion will imply and "I don't support window scaling at
all", which is what the suggested feature field does.
To make things more complicated, until the previous patch I sent, when
Linux would choose a window scale of zero for any reason, it would also
wrongfully report it does not support window scaling at all to the other
side, with some subtle bug caused by it, but this is no longer the
behavior and I believe rightly so.
Thanks,
Gilad
--
Gilad Ben-Yossef
Chief Coffee Drinker & CTO
Codefidence Ltd.
Web: http://codefidence.com
Cell: +972-52-8260388
Skype: gilad_codefidence
Tel: +972-8-9316883 ext. 201
Fax: +972-8-9316884
Email: gilad@codefidence.com
Check out our Open Source technology and training blog - http://tuxology.net
"Sorry cannot parse this, its too long to be true :)"
-- Eric Dumazet on netdev mailing list
^ permalink raw reply
* Re: [PATCH RFC] Per route TCP options
From: Florian Westphal @ 2009-10-21 8:21 UTC (permalink / raw)
To: Gilad Ben-Yossef; +Cc: Rick Jones, netdev, ori
In-Reply-To: <4ADEC076.2030105@codefidence.com>
Gilad Ben-Yossef <gilad@codefidence.com> wrote:
> The point is that even then you are more then likely to wish to turn
> off these options to specific destination and routes (that go over
> said exotic link) and keep using them over others - e.g. timestamp
> OK for local LAN, but for default route that goes over exotic TCP/IP
> over carrier penguins turn it off.
If you need a bandaid solution, its is possible to replace tcp
options with NOOPs using netfilters TCPOPTSTRIP target.
There is also an ECN target to work around ECN blackholes.
^ permalink raw reply
* Re: [PATCH RFC] Per route TCP options
From: Gilad Ben-Yossef @ 2009-10-21 8:27 UTC (permalink / raw)
To: Bill Fink; +Cc: netdev, ori
In-Reply-To: <20091020221354.5a714323.billfink@mindspring.com>
Hi,
Bill Fink wrote:
> On Tue, 20 Oct 2009, Gilad Ben-Yossef wrote:
>
>
>> Turn the global sysctls allowing disabling of TCP SACK, DSCAK,
>> time stamp and window scale into per route entry feature options,
>> laying the ground to future removal of the relevant global sysctls.
>>
>> You really only want to disable SACK, DSACK, time stamp or window
>> scale if you've got a piece of broken networking equipment somewhere
>> as a stop gap until you can bring a big enough hammer to deal with
>> the broken network equipment. It doesn't make sense to "punish" the
>> entire connections going through the machine to destinations not
>> related to the broken equipment.
>>
>
> For certain test situations, it is sometimes desirable to globally
> disable TCP timestamps. Although I have not personally wanted to
> globally disable the other mentioned features, I can imagine test
> scenarios where it could be useful. Admittedly it could also be
> accomplished with per route features, just not as conveniently,
> especially if there are a large number of interfaces and/or routes.
>
>
I don't feel that strongly about it either way, just trying to hearken to
Linus "Linux is bloated" message by not fostering duplicate ways to do
the same thing... ;-)
If the consensus is to adopt the route features but leave the global
kill switches, I certainly have no problem with that.
Thanks,
Gilad
--
Gilad Ben-Yossef
Chief Coffee Drinker & CTO
Codefidence Ltd.
Web: http://codefidence.com
Cell: +972-52-8260388
Skype: gilad_codefidence
Tel: +972-8-9316883 ext. 201
Fax: +972-8-9316884
Email: gilad@codefidence.com
Check out our Open Source technology and training blog - http://tuxology.net
"Sorry cannot parse this, its too long to be true :)"
-- Eric Dumazet on netdev mailing list
^ permalink raw reply
* Re: [PATCH RFC] Per route TCP options
From: Gilad Ben-Yossef @ 2009-10-21 8:40 UTC (permalink / raw)
To: Florian Westphal; +Cc: Rick Jones, netdev, ori
In-Reply-To: <20091021082109.GE8704@Chamillionaire.breakpoint.cc>
Hi Florian,
Florian Westphal wrote:
> Gilad Ben-Yossef <gilad@codefidence.com> wrote:
>
>> The point is that even then you are more then likely to wish to turn
>> off these options to specific destination and routes (that go over
>> said exotic link) and keep using them over others - e.g. timestamp
>> OK for local LAN, but for default route that goes over exotic TCP/IP
>> over carrier penguins turn it off.
>>
>
> If you need a bandaid solution, its is possible to replace tcp
> options with NOOPs using netfilters TCPOPTSTRIP target.
>
> There is also an ECN target to work around ECN blackholes.
>
Thanks for the tip. It is appreciated.
The band aid solution that Ori and company found was
simply to patch the local copy of the kernel used but being that sitting
on a bunch of "private" patches seems like a lose-lose situation (there
is a term you don't hear much when talking to MBAs :-) I'm now trying
to get it mainlined for them.
Thanks,
Gilad
--
Gilad Ben-Yossef
Chief Coffee Drinker & CTO
Codefidence Ltd.
Web: http://codefidence.com
Cell: +972-52-8260388
Skype: gilad_codefidence
Tel: +972-8-9316883 ext. 201
Fax: +972-8-9316884
Email: gilad@codefidence.com
Check out our Open Source technology and training blog - http://tuxology.net
"Sorry cannot parse this, its too long to be true :)"
-- Eric Dumazet on netdev mailing list
^ permalink raw reply
* Re: Policy routing + route "via" gives a strange behavior
From: Mallika Gautam @ 2009-10-21 8:47 UTC (permalink / raw)
To: Guido Trotter; +Cc: Atis Elsts, netdev
In-Reply-To: <20091020172334.GA6404@gg.studio.tixteam.net>
>
>> Anyway, you can achieve what you wish by using the "onlink" option, e.g.:
>> ip route add table 100 default dev eth1 via 192.168.5.254 onlink
>
Hi,
I am facing exactly the same issue and have to flush the main table
once the routes in the table get added. This is really nasty as I need
to this from a kernel module every time an interface is shutdown and
again brought up.
"onlink" doesn't seem to work as it "sees" the destination IP address
"onlink" instead of resolving it via the gateway. E.g. if I want to
ping 139.85.111.12 via eth1, it tries to send ARP request for
139.85.111.12 and not 192.168.5.254. So it doesn' work.
I would really link to see this behaviour fixed as the workarounds are
equally painful.
Regards
Mallika
^ permalink raw reply
* [PATCH v2 0/8] Per route TCP options
From: Gilad Ben-Yossef @ 2009-10-21 8:56 UTC (permalink / raw)
To: netdev; +Cc: ori, Gilad Ben-Yossef
Turn the global sysctls allowing disabling of TCP SACK, DSCAK,
time stamp and window scale into per route entry feature options,
laying the ground to future removal of the relevant global sysctls.
You really only want to disable SACK, DSACK, time stamp or window
scale if you've got a piece of broken networking equipment somewhere
as a stop gap until you can bring a big enough hammer to deal with
the broken network equipment. It doesn't make sense to "punish" the
entire connections going through the machine to destinations not
related to the broken equipment.
This is doubly true when you're dealing with network containers
used to isolate several virtual domains.
Per route options implemented in free bits in the features route
entry property, which in some cases were reserved by name for these
options, so this does not inflate any structure and I expect that
when the apropriate global sysctls will be removed the overall code
base will be smaller.
Tested on x86 using Qemu/KVM.
Will send the matching patch to iproute2 if/when this is ACKed or
if someone wants to test this.
Patchset based on original work by Ori Finkelman and Yony Amit
from ComSleep Ltd.
Gilad Ben-Yossef (8):
Only parse time stamp TCP option in time wait sock
Allow tcp_parse_options to consult dst entry
Infrastructure for querying route entry features
Add the no SACK route option feature
Allow disabling TCP timestamp options per route
Allow to turn off TCP window scale opt per route
Allow disabling of DSACK TCP option per route
Document future removal of sysctl_tcp_* options
Documentation/feature-removal-schedule.txt | 12 ++++++++++++
include/linux/rtnetlink.h | 6 ++++--
include/net/dst.h | 8 +++++++-
include/net/tcp.h | 3 ++-
net/ipv4/syncookies.c | 27 ++++++++++++++-------------
net/ipv4/tcp_input.c | 26 ++++++++++++++++++--------
net/ipv4/tcp_ipv4.c | 19 ++++++++++---------
net/ipv4/tcp_minisocks.c | 8 +++++---
net/ipv4/tcp_output.c | 18 +++++++++++++-----
net/ipv6/syncookies.c | 28 +++++++++++++++-------------
net/ipv6/tcp_ipv6.c | 3 ++-
11 files changed, 102 insertions(+), 56 deletions(-)
^ permalink raw reply
* [PATCH v2 3/8] Add dst_feature to query route entry features
From: Gilad Ben-Yossef @ 2009-10-21 8:56 UTC (permalink / raw)
To: netdev; +Cc: ori, Gilad Ben-Yossef
In-Reply-To: <1256115421-12714-1-git-send-email-gilad@codefidence.com>
Adding an accessor to existing dst_entry feautres field and
refactor the only supported feature (allfrag) to use it.
Signed-off-by: Gilad Ben-Yossef <gilad@codefidence.com>
Sigend-off-by: Ori Finkelman <ori@comsleep.com>
Sigend-off-by: Yony Amit <yony@comsleep.com>
---
include/net/dst.h | 8 +++++++-
1 files changed, 7 insertions(+), 1 deletions(-)
diff --git a/include/net/dst.h b/include/net/dst.h
index 5a900dd..b562be3 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -111,6 +111,12 @@ dst_metric(const struct dst_entry *dst, int metric)
return dst->metrics[metric-1];
}
+static inline u32
+dst_feature(const struct dst_entry *dst, u32 feature)
+{
+ return dst_metric(dst, RTAX_FEATURES) & feature;
+}
+
static inline u32 dst_mtu(const struct dst_entry *dst)
{
u32 mtu = dst_metric(dst, RTAX_MTU);
@@ -136,7 +142,7 @@ static inline void set_dst_metric_rtt(struct dst_entry *dst, int metric,
static inline u32
dst_allfrag(const struct dst_entry *dst)
{
- int ret = dst_metric(dst, RTAX_FEATURES) & RTAX_FEATURE_ALLFRAG;
+ int ret = dst_feature(dst, RTAX_FEATURE_ALLFRAG);
/* Yes, _exactly_. This is paranoia. */
barrier();
return ret;
--
1.5.6.3
^ permalink raw reply related
* [PATCH v2 8/8] Document future removal of sysctl_tcp_* options
From: Gilad Ben-Yossef @ 2009-10-21 8:57 UTC (permalink / raw)
To: netdev; +Cc: ori, Gilad Ben-Yossef
In-Reply-To: <1256115421-12714-1-git-send-email-gilad@codefidence.com>
No need for global kill switches if we have per route entry controls.
Wait a year before removing in case someone is using this.
Signed-off-by: Gilad Ben-Yossef <gilad@codefidence.com>
---
Documentation/feature-removal-schedule.txt | 12 ++++++++++++
1 files changed, 12 insertions(+), 0 deletions(-)
diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt
index 89a47b5..60db855 100644
--- a/Documentation/feature-removal-schedule.txt
+++ b/Documentation/feature-removal-schedule.txt
@@ -6,6 +6,18 @@ be removed from this file.
---------------------------
+What: sysctl_tcp_sack, sysctl_tcp_timestamps, sysctl_tcp_window_scaling,
+ sysctl_tcp_dsack
+When: October 2010
+
+Why: These options can now be set on a per route basis via the
+ RTAX_FEATURE_NO_SACK, RTAX_FEATURE_NO_TSTAMP, RTAX_FEATURE_NO_WSCALE,
+ and RTAX_FEATURE_NO_DSACK route feature options.
+
+Who: Gilad Ben-Yossef <gilad@codefidence.com>
+
+---------------------------
+
What: PRISM54
When: 2.6.34
--
1.5.6.3
^ permalink raw reply related
* [PATCH v2 6/8] Allow to turn off TCP window scale opt per route
From: Gilad Ben-Yossef @ 2009-10-21 8:56 UTC (permalink / raw)
To: netdev; +Cc: ori, Gilad Ben-Yossef
In-Reply-To: <1256115421-12714-1-git-send-email-gilad@codefidence.com>
Add and use no window scale bit in the features field.
Note that this is not the same as setting a window scale of 0
as would happen with window limit on route.
Signed-off-by: Gilad Ben-Yossef <gilad@codefidence.com>
Sigend-off-by: Ori Finkelman <ori@comsleep.com>
Sigend-off-by: Yony Amit <yony@comsleep.com>
---
include/linux/rtnetlink.h | 1 +
net/ipv4/tcp_input.c | 3 ++-
net/ipv4/tcp_output.c | 6 ++++--
3 files changed, 7 insertions(+), 3 deletions(-)
diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h
index 2ab8c75..6784b34 100644
--- a/include/linux/rtnetlink.h
+++ b/include/linux/rtnetlink.h
@@ -380,6 +380,7 @@ enum
#define RTAX_FEATURE_NO_SACK 0x00000002
#define RTAX_FEATURE_NO_TSTAMP 0x00000004
#define RTAX_FEATURE_ALLFRAG 0x00000008
+#define RTAX_FEATURE_NO_WSCALE 0x00000010
struct rta_session
{
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index d2f9742..4f5e914 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -3739,7 +3739,8 @@ void tcp_parse_options(struct sk_buff *skb, struct tcp_options_received *opt_rx,
break;
case TCPOPT_WINDOW:
if (opsize == TCPOLEN_WINDOW && th->syn &&
- !estab && sysctl_tcp_window_scaling) {
+ !estab && sysctl_tcp_window_scaling &&
+ !dst_feature(dst, RTAX_FEATURE_NO_WSCALE)) {
__u8 snd_wscale = *(__u8 *)ptr;
opt_rx->wscale_ok = 1;
if (snd_wscale > 14) {
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 8f30c18..ff60a21 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -496,7 +496,8 @@ static unsigned tcp_syn_options(struct sock *sk, struct sk_buff *skb,
opts->tsecr = tp->rx_opt.ts_recent;
size += TCPOLEN_TSTAMP_ALIGNED;
}
- if (likely(sysctl_tcp_window_scaling)) {
+ if (likely(sysctl_tcp_window_scaling &&
+ !dst_feature(dst, RTAX_FEATURE_NO_WSCALE))) {
opts->ws = tp->rx_opt.rcv_wscale;
opts->options |= OPTION_WSCALE;
size += TCPOLEN_WSCALE_ALIGNED;
@@ -2347,7 +2348,8 @@ static void tcp_connect_init(struct sock *sk)
tp->advmss - (tp->rx_opt.ts_recent_stamp ? tp->tcp_header_len - sizeof(struct tcphdr) : 0),
&tp->rcv_wnd,
&tp->window_clamp,
- sysctl_tcp_window_scaling,
+ (sysctl_tcp_window_scaling &&
+ !dst_feature(dst, RTAX_FEATURE_NO_WSCALE)),
&rcv_wscale);
tp->rx_opt.rcv_wscale = rcv_wscale;
--
1.5.6.3
^ permalink raw reply related
* [PATCH v2 4/8] Add the no SACK route option feature
From: Gilad Ben-Yossef @ 2009-10-21 8:56 UTC (permalink / raw)
To: netdev; +Cc: ori, Gilad Ben-Yossef
In-Reply-To: <1256115421-12714-1-git-send-email-gilad@codefidence.com>
Implement querying and acting upon the no sack bit in the features
field.
Signed-off-by: Gilad Ben-Yossef <gilad@codefidence.com>
Sigend-off-by: Ori Finkelman <ori@comsleep.com>
Sigend-off-by: Yony Amit <yony@comsleep.com>
---
include/linux/rtnetlink.h | 2 +-
net/ipv4/tcp_input.c | 3 ++-
net/ipv4/tcp_output.c | 4 +++-
3 files changed, 6 insertions(+), 3 deletions(-)
diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h
index adf2068..9c802a6 100644
--- a/include/linux/rtnetlink.h
+++ b/include/linux/rtnetlink.h
@@ -377,7 +377,7 @@ enum
#define RTAX_MAX (__RTAX_MAX - 1)
#define RTAX_FEATURE_ECN 0x00000001
-#define RTAX_FEATURE_SACK 0x00000002
+#define RTAX_FEATURE_NO_SACK 0x00000002
#define RTAX_FEATURE_TIMESTAMP 0x00000004
#define RTAX_FEATURE_ALLFRAG 0x00000008
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index d502f49..b14f780 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -3763,7 +3763,8 @@ void tcp_parse_options(struct sk_buff *skb, struct tcp_options_received *opt_rx,
break;
case TCPOPT_SACK_PERM:
if (opsize == TCPOLEN_SACK_PERM && th->syn &&
- !estab && sysctl_tcp_sack) {
+ !estab && sysctl_tcp_sack &&
+ !dst_feature(dst, RTAX_FEATURE_NO_SACK)) {
opt_rx->sack_ok = 1;
tcp_sack_reset(opt_rx);
}
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index fcd278a..64db8dd 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -464,6 +464,7 @@ static unsigned tcp_syn_options(struct sock *sk, struct sk_buff *skb,
struct tcp_md5sig_key **md5) {
struct tcp_sock *tp = tcp_sk(sk);
unsigned size = 0;
+ struct dst_entry *dst = __sk_dst_get(sk);
#ifdef CONFIG_TCP_MD5SIG
*md5 = tp->af_specific->md5_lookup(sk, sk);
@@ -498,7 +499,8 @@ static unsigned tcp_syn_options(struct sock *sk, struct sk_buff *skb,
opts->options |= OPTION_WSCALE;
size += TCPOLEN_WSCALE_ALIGNED;
}
- if (likely(sysctl_tcp_sack)) {
+ if (likely(sysctl_tcp_sack &&
+ !dst_feature(dst, RTAX_FEATURE_NO_SACK))) {
opts->options |= OPTION_SACK_ADVERTISE;
if (unlikely(!(OPTION_TS & opts->options)))
size += TCPOLEN_SACKPERM_ALIGNED;
--
1.5.6.3
^ permalink raw reply related
* [PATCH v2 1/8] Only parse time stamp TCP option in time wait sock
From: Gilad Ben-Yossef @ 2009-10-21 8:56 UTC (permalink / raw)
To: netdev; +Cc: ori, Gilad Ben-Yossef, Yony Amit
In-Reply-To: <1256115421-12714-1-git-send-email-gilad@codefidence.com>
A time wait socket is established - we already know if time stamp
option is called for or not.
Signed-off-by: Gilad Ben-Yossef <gilad@codefidence.com>
Signed-off-by: Ori Finkelman <ori@comsleep.com>
Signed-off-by: Yony Amit <yony@comsleep.com>
---
net/ipv4/tcp_minisocks.c | 3 +--
1 files changed, 1 insertions(+), 2 deletions(-)
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index 624c3c9..c49a550 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -100,9 +100,8 @@ tcp_timewait_state_process(struct inet_timewait_sock *tw, struct sk_buff *skb,
struct tcp_options_received tmp_opt;
int paws_reject = 0;
- tmp_opt.saw_tstamp = 0;
if (th->doff > (sizeof(*th) >> 2) && tcptw->tw_ts_recent_stamp) {
- tcp_parse_options(skb, &tmp_opt, 0);
+ tcp_parse_options(skb, &tmp_opt, 1);
if (tmp_opt.saw_tstamp) {
tmp_opt.ts_recent = tcptw->tw_ts_recent;
--
1.5.6.3
^ permalink raw reply related
* [PATCH v2 2/8] Allow tcp_parse_options to consult dst entry
From: Gilad Ben-Yossef @ 2009-10-21 8:56 UTC (permalink / raw)
To: netdev; +Cc: ori, Gilad Ben-Yossef
In-Reply-To: <1256115421-12714-1-git-send-email-gilad@codefidence.com>
We need tcp_parse_options to be aware of dst_entry to
take into account per dst_entry TCP options settings
Signed-off-by: Gilad Ben-Yossef <gilad@codefidence.com>
Sigend-off-by: Ori Finkelman <ori@comsleep.com>
Sigend-off-by: Yony Amit <yony@comsleep.com>
---
include/net/tcp.h | 3 ++-
net/ipv4/syncookies.c | 27 ++++++++++++++-------------
net/ipv4/tcp_input.c | 9 ++++++---
net/ipv4/tcp_ipv4.c | 19 ++++++++++---------
net/ipv4/tcp_minisocks.c | 7 +++++--
net/ipv6/syncookies.c | 28 +++++++++++++++-------------
net/ipv6/tcp_ipv6.c | 3 ++-
7 files changed, 54 insertions(+), 42 deletions(-)
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 03a49c7..740d09b 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -409,7 +409,8 @@ extern int tcp_recvmsg(struct kiocb *iocb, struct sock *sk,
extern void tcp_parse_options(struct sk_buff *skb,
struct tcp_options_received *opt_rx,
- int estab);
+ int estab,
+ struct dst_entry *dst);
extern u8 *tcp_parse_md5sig_option(struct tcphdr *th);
diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c
index a6e0e07..4990dd4 100644
--- a/net/ipv4/syncookies.c
+++ b/net/ipv4/syncookies.c
@@ -276,13 +276,6 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb,
NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_SYNCOOKIESRECV);
- /* check for timestamp cookie support */
- memset(&tcp_opt, 0, sizeof(tcp_opt));
- tcp_parse_options(skb, &tcp_opt, 0);
-
- if (tcp_opt.saw_tstamp)
- cookie_check_timestamp(&tcp_opt);
-
ret = NULL;
req = inet_reqsk_alloc(&tcp_request_sock_ops); /* for safety */
if (!req)
@@ -298,12 +291,6 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb,
ireq->loc_addr = ip_hdr(skb)->daddr;
ireq->rmt_addr = ip_hdr(skb)->saddr;
ireq->ecn_ok = 0;
- ireq->snd_wscale = tcp_opt.snd_wscale;
- ireq->rcv_wscale = tcp_opt.rcv_wscale;
- ireq->sack_ok = tcp_opt.sack_ok;
- ireq->wscale_ok = tcp_opt.wscale_ok;
- ireq->tstamp_ok = tcp_opt.saw_tstamp;
- req->ts_recent = tcp_opt.saw_tstamp ? tcp_opt.rcv_tsval : 0;
/* We throwed the options of the initial SYN away, so we hope
* the ACK carries the same options again (see RFC1122 4.2.3.8)
@@ -351,6 +338,20 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb,
}
}
+ /* check for timestamp cookie support */
+ memset(&tcp_opt, 0, sizeof(tcp_opt));
+ tcp_parse_options(skb, &tcp_opt, 0, &rt->u.dst);
+
+ if (tcp_opt.saw_tstamp)
+ cookie_check_timestamp(&tcp_opt);
+
+ ireq->snd_wscale = tcp_opt.snd_wscale;
+ ireq->rcv_wscale = tcp_opt.rcv_wscale;
+ ireq->sack_ok = tcp_opt.sack_ok;
+ ireq->wscale_ok = tcp_opt.wscale_ok;
+ ireq->tstamp_ok = tcp_opt.saw_tstamp;
+ req->ts_recent = tcp_opt.saw_tstamp ? tcp_opt.rcv_tsval : 0;
+
/* Try to redo what tcp_v4_send_synack did. */
req->window_clamp = tp->window_clamp ? :dst_metric(&rt->u.dst, RTAX_WINDOW);
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index d86784b..d502f49 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -3698,12 +3698,14 @@ old_ack:
* the fast version below fails.
*/
void tcp_parse_options(struct sk_buff *skb, struct tcp_options_received *opt_rx,
- int estab)
+ int estab, struct dst_entry *dst)
{
unsigned char *ptr;
struct tcphdr *th = tcp_hdr(skb);
int length = (th->doff * 4) - sizeof(struct tcphdr);
+ BUG_ON(!estab && !dst);
+
ptr = (unsigned char *)(th + 1);
opt_rx->saw_tstamp = 0;
@@ -3820,7 +3822,7 @@ static int tcp_fast_parse_options(struct sk_buff *skb, struct tcphdr *th,
if (tcp_parse_aligned_timestamp(tp, th))
return 1;
}
- tcp_parse_options(skb, &tp->rx_opt, 1);
+ tcp_parse_options(skb, &tp->rx_opt, 1, NULL);
return 1;
}
@@ -5364,8 +5366,9 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb,
struct tcp_sock *tp = tcp_sk(sk);
struct inet_connection_sock *icsk = inet_csk(sk);
int saved_clamp = tp->rx_opt.mss_clamp;
+ struct dst_entry *dst = __sk_dst_get(sk);
- tcp_parse_options(skb, &tp->rx_opt, 0);
+ tcp_parse_options(skb, &tp->rx_opt, 0, dst);
if (th->ack) {
/* rfc793:
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 7cda24b..1cb0ec4 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1256,11 +1256,18 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
tcp_rsk(req)->af_specific = &tcp_request_sock_ipv4_ops;
#endif
+ ireq = inet_rsk(req);
+ ireq->loc_addr = daddr;
+ ireq->rmt_addr = saddr;
+ ireq->no_srccheck = inet_sk(sk)->transparent;
+ ireq->opt = tcp_v4_save_options(sk, skb);
+
+ dst = inet_csk_route_req(sk, req);
tcp_clear_options(&tmp_opt);
tmp_opt.mss_clamp = 536;
tmp_opt.user_mss = tcp_sk(sk)->rx_opt.user_mss;
- tcp_parse_options(skb, &tmp_opt, 0);
+ tcp_parse_options(skb, &tmp_opt, 0, dst);
if (want_cookie && !tmp_opt.saw_tstamp)
tcp_clear_options(&tmp_opt);
@@ -1269,14 +1276,8 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
tcp_openreq_init(req, &tmp_opt, skb);
- ireq = inet_rsk(req);
- ireq->loc_addr = daddr;
- ireq->rmt_addr = saddr;
- ireq->no_srccheck = inet_sk(sk)->transparent;
- ireq->opt = tcp_v4_save_options(sk, skb);
-
if (security_inet_conn_request(sk, skb, req))
- goto drop_and_free;
+ goto drop_and_release;
if (!want_cookie)
TCP_ECN_create_request(req, tcp_hdr(skb));
@@ -1301,7 +1302,7 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
*/
if (tmp_opt.saw_tstamp &&
tcp_death_row.sysctl_tw_recycle &&
- (dst = inet_csk_route_req(sk, req)) != NULL &&
+ dst != NULL &&
(peer = rt_get_peer((struct rtable *)dst)) != NULL &&
peer->v4daddr == saddr) {
if (get_seconds() < peer->tcp_ts_stamp + TCP_PAWS_MSL &&
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index c49a550..70ff955 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -101,7 +101,7 @@ tcp_timewait_state_process(struct inet_timewait_sock *tw, struct sk_buff *skb,
int paws_reject = 0;
if (th->doff > (sizeof(*th) >> 2) && tcptw->tw_ts_recent_stamp) {
- tcp_parse_options(skb, &tmp_opt, 1);
+ tcp_parse_options(skb, &tmp_opt, 1, NULL);
if (tmp_opt.saw_tstamp) {
tmp_opt.ts_recent = tcptw->tw_ts_recent;
@@ -499,10 +499,11 @@ struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb,
int paws_reject = 0;
struct tcp_options_received tmp_opt;
struct sock *child;
+ struct dst_entry *dst = inet_csk_route_req(sk, req);
tmp_opt.saw_tstamp = 0;
if (th->doff > (sizeof(struct tcphdr)>>2)) {
- tcp_parse_options(skb, &tmp_opt, 0);
+ tcp_parse_options(skb, &tmp_opt, 0, dst);
if (tmp_opt.saw_tstamp) {
tmp_opt.ts_recent = req->ts_recent;
@@ -515,6 +516,8 @@ struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb,
}
}
+ dst_release(dst);
+
/* Check for pure retransmitted SYN. */
if (TCP_SKB_CB(skb)->seq == tcp_rsk(req)->rcv_isn &&
flg == TCP_FLAG_SYN &&
diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c
index 6b6ae91..6ece408 100644
--- a/net/ipv6/syncookies.c
+++ b/net/ipv6/syncookies.c
@@ -184,13 +184,6 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_SYNCOOKIESRECV);
- /* check for timestamp cookie support */
- memset(&tcp_opt, 0, sizeof(tcp_opt));
- tcp_parse_options(skb, &tcp_opt, 0);
-
- if (tcp_opt.saw_tstamp)
- cookie_check_timestamp(&tcp_opt);
-
ret = NULL;
req = inet6_reqsk_alloc(&tcp6_request_sock_ops);
if (!req)
@@ -224,12 +217,6 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
req->expires = 0UL;
req->retrans = 0;
ireq->ecn_ok = 0;
- ireq->snd_wscale = tcp_opt.snd_wscale;
- ireq->rcv_wscale = tcp_opt.rcv_wscale;
- ireq->sack_ok = tcp_opt.sack_ok;
- ireq->wscale_ok = tcp_opt.wscale_ok;
- ireq->tstamp_ok = tcp_opt.saw_tstamp;
- req->ts_recent = tcp_opt.saw_tstamp ? tcp_opt.rcv_tsval : 0;
treq->rcv_isn = ntohl(th->seq) - 1;
treq->snt_isn = cookie;
@@ -264,6 +251,21 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
goto out_free;
}
+ /* check for timestamp cookie support */
+ memset(&tcp_opt, 0, sizeof(tcp_opt));
+ tcp_parse_options(skb, &tcp_opt, 0, dst);
+
+ if (tcp_opt.saw_tstamp)
+ cookie_check_timestamp(&tcp_opt);
+
+ req->ts_recent = tcp_opt.saw_tstamp ? tcp_opt.rcv_tsval : 0;
+
+ ireq->snd_wscale = tcp_opt.snd_wscale;
+ ireq->rcv_wscale = tcp_opt.rcv_wscale;
+ ireq->sack_ok = tcp_opt.sack_ok;
+ ireq->wscale_ok = tcp_opt.wscale_ok;
+ ireq->tstamp_ok = tcp_opt.saw_tstamp;
+
req->window_clamp = tp->window_clamp ? :dst_metric(dst, RTAX_WINDOW);
tcp_select_initial_window(tcp_full_space(sk), req->mss,
&req->rcv_wnd, &req->window_clamp,
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 21d100b..2eebab5 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1165,6 +1165,7 @@ static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
struct tcp_sock *tp = tcp_sk(sk);
struct request_sock *req = NULL;
__u32 isn = TCP_SKB_CB(skb)->when;
+ struct dst_entry *dst = __sk_dst_get(sk);
#ifdef CONFIG_SYN_COOKIES
int want_cookie = 0;
#else
@@ -1203,7 +1204,7 @@ static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
tmp_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
tmp_opt.user_mss = tp->rx_opt.user_mss;
- tcp_parse_options(skb, &tmp_opt, 0);
+ tcp_parse_options(skb, &tmp_opt, 0, dst);
if (want_cookie && !tmp_opt.saw_tstamp)
tcp_clear_options(&tmp_opt);
--
1.5.6.3
^ permalink raw reply related
* [PATCH v2 7/8] Allow disabling of DSACK TCP option per route
From: Gilad Ben-Yossef @ 2009-10-21 8:57 UTC (permalink / raw)
To: netdev; +Cc: ori, Gilad Ben-Yossef
In-Reply-To: <1256115421-12714-1-git-send-email-gilad@codefidence.com>
Add and use no DSCAK bit in the features field.
Signed-off-by: Gilad Ben-Yossef <gilad@codefidence.com>
Sigend-off-by: Ori Finkelman <ori@comsleep.com>
Sigend-off-by: Yony Amit <yony@comsleep.com>
---
include/linux/rtnetlink.h | 1 +
net/ipv4/tcp_input.c | 8 ++++++--
2 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h
index 6784b34..e78b60c 100644
--- a/include/linux/rtnetlink.h
+++ b/include/linux/rtnetlink.h
@@ -381,6 +381,7 @@ enum
#define RTAX_FEATURE_NO_TSTAMP 0x00000004
#define RTAX_FEATURE_ALLFRAG 0x00000008
#define RTAX_FEATURE_NO_WSCALE 0x00000010
+#define RTAX_FEATURE_NO_DSACK 0x00000020
struct rta_session
{
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 4f5e914..4262da5 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -4080,8 +4080,10 @@ static inline int tcp_sack_extend(struct tcp_sack_block *sp, u32 seq,
static void tcp_dsack_set(struct sock *sk, u32 seq, u32 end_seq)
{
struct tcp_sock *tp = tcp_sk(sk);
+ struct dst_entry *dst = __sk_dst_get(sk);
- if (tcp_is_sack(tp) && sysctl_tcp_dsack) {
+ if (tcp_is_sack(tp) && sysctl_tcp_dsack &&
+ !dst_feature(dst, RTAX_FEATURE_NO_DSACK)) {
int mib_idx;
if (before(seq, tp->rcv_nxt))
@@ -4110,13 +4112,15 @@ static void tcp_dsack_extend(struct sock *sk, u32 seq, u32 end_seq)
static void tcp_send_dupack(struct sock *sk, struct sk_buff *skb)
{
struct tcp_sock *tp = tcp_sk(sk);
+ struct dst_entry *dst = __sk_dst_get(sk);
if (TCP_SKB_CB(skb)->end_seq != TCP_SKB_CB(skb)->seq &&
before(TCP_SKB_CB(skb)->seq, tp->rcv_nxt)) {
NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_DELAYEDACKLOST);
tcp_enter_quickack_mode(sk);
- if (tcp_is_sack(tp) && sysctl_tcp_dsack) {
+ if (tcp_is_sack(tp) && sysctl_tcp_dsack &&
+ !dst_feature(dst, RTAX_FEATURE_NO_DSACK)) {
u32 end_seq = TCP_SKB_CB(skb)->end_seq;
if (after(TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt))
--
1.5.6.3
^ permalink raw reply related
* [PATCH v2 5/8] Allow disabling TCP timestamp options per route
From: Gilad Ben-Yossef @ 2009-10-21 8:56 UTC (permalink / raw)
To: netdev; +Cc: ori, Gilad Ben-Yossef
In-Reply-To: <1256115421-12714-1-git-send-email-gilad@codefidence.com>
Implement querying and acting upon the no timestamp bit in the feature
field.
Signed-off-by: Gilad Ben-Yossef <gilad@codefidence.com>
Sigend-off-by: Ori Finkelman <ori@comsleep.com>
Sigend-off-by: Yony Amit <yony@comsleep.com>
---
include/linux/rtnetlink.h | 2 +-
net/ipv4/tcp_input.c | 3 ++-
net/ipv4/tcp_output.c | 8 ++++++--
3 files changed, 9 insertions(+), 4 deletions(-)
diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h
index 9c802a6..2ab8c75 100644
--- a/include/linux/rtnetlink.h
+++ b/include/linux/rtnetlink.h
@@ -378,7 +378,7 @@ enum
#define RTAX_FEATURE_ECN 0x00000001
#define RTAX_FEATURE_NO_SACK 0x00000002
-#define RTAX_FEATURE_TIMESTAMP 0x00000004
+#define RTAX_FEATURE_NO_TSTAMP 0x00000004
#define RTAX_FEATURE_ALLFRAG 0x00000008
struct rta_session
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index b14f780..d2f9742 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -3755,7 +3755,8 @@ void tcp_parse_options(struct sk_buff *skb, struct tcp_options_received *opt_rx,
case TCPOPT_TIMESTAMP:
if ((opsize == TCPOLEN_TIMESTAMP) &&
((estab && opt_rx->tstamp_ok) ||
- (!estab && sysctl_tcp_timestamps))) {
+ (!estab && sysctl_tcp_timestamps &&
+ !dst_feature(dst, RTAX_FEATURE_NO_TSTAMP)))) {
opt_rx->saw_tstamp = 1;
opt_rx->rcv_tsval = get_unaligned_be32(ptr);
opt_rx->rcv_tsecr = get_unaligned_be32(ptr + 4);
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 64db8dd..8f30c18 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -488,7 +488,9 @@ static unsigned tcp_syn_options(struct sock *sk, struct sk_buff *skb,
opts->mss = tcp_advertise_mss(sk);
size += TCPOLEN_MSS_ALIGNED;
- if (likely(sysctl_tcp_timestamps && *md5 == NULL)) {
+ if (likely(sysctl_tcp_timestamps &&
+ !dst_feature(dst, RTAX_FEATURE_NO_TSTAMP) &&
+ *md5 == NULL)) {
opts->options |= OPTION_TS;
opts->tsval = TCP_SKB_CB(skb)->when;
opts->tsecr = tp->rx_opt.ts_recent;
@@ -2317,7 +2319,9 @@ static void tcp_connect_init(struct sock *sk)
* See tcp_input.c:tcp_rcv_state_process case TCP_SYN_SENT.
*/
tp->tcp_header_len = sizeof(struct tcphdr) +
- (sysctl_tcp_timestamps ? TCPOLEN_TSTAMP_ALIGNED : 0);
+ (sysctl_tcp_timestamps &&
+ (!dst_feature(dst, RTAX_FEATURE_NO_TSTAMP) ?
+ TCPOLEN_TSTAMP_ALIGNED : 0));
#ifdef CONFIG_TCP_MD5SIG
if (tp->af_specific->md5_lookup(sk, sk) != NULL)
--
1.5.6.3
^ permalink raw reply related
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